DE102022108701A1 - Device and method for determining the mass of an occupant of a vehicle - Google Patents

Abstract

The invention relates to a device (6) and a method for determining a mass of an occupant (2) of a vehicle (1), the device (6) having: a vehicle acceleration detection device (7) which determines a vehicle acceleration vector (24) which is a describes acceleration experienced by the vehicle (1); an occupant acceleration detection device (10) which determines an occupant acceleration vector (26) which describes an acceleration experienced by the occupant (2); and an evaluation device (13) which, based on the determined vehicle acceleration vector (24), determines a vehicle force vector (21) which describes a force acting on the vehicle (1), projects the vehicle force vector (21) onto the occupant (2) and outputs it the projected vehicle force vector (22) and the determined occupant acceleration vector (26) determine mass information (36), which describes a mass of the occupant (2).

Description

The invention relates to a device and a method for determining the mass of an occupant of a vehicle.

A vehicle, for example a motor vehicle, may have an inertial measurement unit (IMU), which may alternatively be referred to as an inertial measurement unit. The inertial measuring unit is located, for example, at the location of a center of gravity of the vehicle and can be used to improve comfort functions and/or active safety functions of the vehicle. Alternatively or additionally, the vehicle can have an acceleration sensor. The acceleration sensor can, for example, be designed to detect external vibrations of the vehicle while the vehicle is traveling.

The vehicle can further be designed to detect the presence of a living being, such as a person and/or an animal, in a vehicle interior of the vehicle (English: life presence detection, LPD). Such recognition makes it possible, for example, in a switched off vehicle, in which, for example, an ignition of the vehicle is switched off, to check whether an occupant has remained in the vehicle interior or not. If the presence of a person as a passenger in the vehicle interior has been detected, further information about the person may be of interest, such as their mass, so that, for example, a mass-dependent and thus individualized setting of an airbag of the vehicle can be carried out.

It is the object of the invention to provide a solution by means of which a mass of an occupant of a vehicle can be reliably determined.

The task is solved by the subject matter of the independent patent claims.

A first aspect of the invention relates to a device for determining a mass of an occupant of a vehicle. The occupant is, for example, a person such as a driver, a passenger and/or a person sitting in a back seat of the motor vehicle. The vehicle is, for example, a motor vehicle, for example a passenger car, a truck and/or a passenger bus.

The device has a vehicle acceleration detection device, an occupant acceleration detection device and an evaluation device. The vehicle acceleration detection device is designed to determine a vehicle acceleration vector. In other words, the vehicle acceleration vector can be determined using the vehicle acceleration detection device. The vehicle acceleration vector describes an acceleration experienced by the vehicle. The vehicle acceleration vector, for example, indicates the acceleration of the vehicle in three spatial directions. The three spatial directions could, for example, be specified in a coordinate system of the vehicle acceleration detection device, which corresponds, for example, to a device coordinate system of the device. The vehicle acceleration vector is typically given in Cartesian coordinates. The vehicle acceleration vector preferably indicates the acceleration of the vehicle to a location of a center of mass of the vehicle, in particular if the vehicle acceleration detection device is arranged at the location of the center of mass in the vehicle.

The occupant acceleration detection device is designed to determine an occupant acceleration vector that describes an acceleration experienced by the occupant. In other words, the occupant acceleration vector can be determined using the occupant acceleration detection device. The occupant acceleration vector, for example, indicates in Cartesian coordinates the acceleration that the occupant experiences at his location in the vehicle. The occupant acceleration vector indicates the acceleration that acts at a center of mass of the occupant, which can be referred to, for example, as the center of mass of the occupant's body. It can be provided that the occupant acceleration detection device is different from the vehicle acceleration detection device.

The device therefore preferably provides two different devices, each of which determines an acceleration, the two determined accelerations being able to differ from one another, since the vehicle acceleration vector is determined with one of the two devices and the occupant acceleration vector is determined with the other.

The evaluation device is designed to determine a vehicle force vector based on the determined vehicle acceleration vector. The vehicle force vector describes a force acting on the vehicle. The vehicle force vector describes in particular the force acting at the vehicle's center of mass. In addition, the evaluation device is designed to project the vehicle force vector onto the occupant. It therefore becomes a projected vehicle force vector determined, which does not describe the force acting at the vehicle's center of mass, but rather the force that actually acts on the occupant at the location of the occupant. The projected vehicle force vector can therefore alternatively be referred to as the occupant force vector, which describes the force acting on the occupant at his or her location. The force vector is projected using known vector projection methods. The evaluation device is also designed to determine mass information from the projected vehicle force vector and the determined occupant acceleration vector, the mass information describing a mass of the occupant. The mass information can be in the form of mass data, the mass data in particular having at least one mass value. The relationship between the projected vehicle force vector, i.e. the force acting on the occupant, and the occupant acceleration vector, i.e. the acceleration acting on the occupant, is ultimately given by Newton's laws. Accordingly, the force vector can be calculated from the product of the acceleration vector with the mass of the body on which the force and acceleration act. Ultimately, the vehicle force vector can be determined by means of the evaluation device based on the determined vehicle acceleration vector, the vehicle force vector can be projected onto the occupant and the mass information can be determined from the projected vehicle force vector and the determined occupant acceleration vector.

The mass information can merely be an estimate of the actual mass of the occupant, with a distinction being made in particular between several different mass ranges. The different mass ranges can be made available for further evaluation using the evaluation device and/or another control device of the vehicle. For example, if the mass information is greater than 0 kilograms and less than 10 kilograms, it can be concluded that it is a small child, if the mass information is between 10 kilograms and 50 kilograms it is a child, and if the mass information is greater than 50 kilograms it can be concluded that it is an adult. A child is defined here as a person from the age of four to 18, which means the child can be a teenager, for example. A toddler is also understood to mean a newborn or an infant, that is, a person who is under four years old. Based on the determined mass information, for example, an airbag function of the vehicle can be automatically deactivated, in particular locally, if the person detected is, for example, a small child, and / or a time-dependent warning message can be provided, for example, if a vehicle has been left behind in a switched off vehicle Toddler or child was detected. Ultimately, the determined mass information is made available for further functions of the vehicle.

By detecting both the acceleration acting on the vehicle and the acceleration acting on the occupant and the subsequent evaluation of the corresponding data to determine the mass information, a device is provided by means of which the mass of the occupant of the vehicle can be reliably determined. The device can also be based on devices already present in the vehicle, since devices for detecting acceleration and the evaluation device are typical for the vehicle. The device can therefore be implemented particularly simply and cost-effectively.

The device according to the invention can be understood as a device arrangement, the device arrangement comprising the device already described and the vehicle with at least one occupant. Furthermore, the first aspect of the invention can be understood as a system for determining a mass of an occupant of a vehicle. It is envisaged that the system uses a vehicle acceleration detection device to determine a vehicle acceleration vector that describes an acceleration experienced by the vehicle; using an occupant acceleration detection device to determine an occupant acceleration vector which describes an acceleration experienced by the occupant; and by means of an evaluation device based on the determined vehicle acceleration vector, determines a vehicle force vector that describes a force acting on the vehicle, projects the vehicle force vector onto the occupant and determines mass information that describes a mass of the occupant from the projected vehicle force vector and the determined occupant acceleration vector.

An advantageous exemplary embodiment provides that the occupant acceleration detection device is designed as a radar sensor and/or camera. The determination of the occupant acceleration vector can therefore be radar-based and/or camera-based or image-based. The radar sensor can, for example, have at least one transmitting antenna and at least one receiving antenna, in particular several receiving antennas. The radar sensor can, for example, be arranged centrally on an inner wall of a ceiling of the vehicle in the vehicle interior in a vehicle longitudinal direction and a vehicle transverse direction. The radar sensor is preferably arranged in such a way that all vehicle seats in the vehicle interior can be at least partially detected by means of the radar sensor. The camera can be used as a vehicle interior Space camera can be designed, which can be arranged, for example, spatially close to the radar sensor, in particular at the same location as the radar sensor. Alternatively or additionally, the camera can be positioned, for example, in a front area of the vehicle on a ceiling area there. The camera is designed to provide static and/or moving image data that describes the vehicle interior, in particular at least partially an area of the respective vehicle seat in the vehicle interior. The image data provided can be referred to as camera data. Alternatively or additionally, several radar sensors and/or cameras arranged at a spatial distance from one another can be provided in the vehicle interior. Ultimately, the occupant acceleration information is determined from measurement data from the radar sensor and/or the camera recorded in the vehicle interior. Since both the radar sensor and the camera can be found in the vehicle interior in many vehicles, a particularly cost-effective and easy-to-implement design of the occupant acceleration detection device is chosen for the device.

Furthermore, an exemplary embodiment provides that the vehicle acceleration detection device is designed as an acceleration sensor and/or inertial measuring unit. The inertial measurement unit (IMU) can alternatively be referred to as an inertial measurement unit or inertial sensor. The inertial measuring unit has, for example, several inertial sensors, such as acceleration sensors and/or rotation rate sensors. The acceleration sensor and/or the inertial measuring unit can be arranged, for example, in the area of a center of mass of the vehicle. Alternatively or additionally, at least one of the two possible vehicle acceleration detection devices can be arranged spatially close to and/or at the same location as the occupant acceleration detection device on the ceiling of the vehicle. The vehicle acceleration detection device can, for example, comprise a plurality of acceleration sensors in the vehicle, which can be arranged at a spatial distance from one another. Since the acceleration sensor and/or the inertial measuring unit is often provided as standard in the vehicle, the described embodiment provides a particularly cost-effective and easy-to-implement vehicle acceleration detection device for the device.

In addition, an exemplary embodiment provides that the device has an occupant presence detection device. The occupant presence detection device is in particular a pressure sensor and/or a seat belt buckle sensor. The pressure sensor is arranged in a vehicle seat of the vehicle. The pressure sensor is designed to detect whether an occupant is sitting on the vehicle seat or not. The pressure sensor can determine this by evaluating pressure information recorded by it, which describes the pressure acting on the vehicle seat. The seat belt buckle sensor is, for example, integrated into a seat belt buckle or at least assigned to it. The seat belt buckle sensor is designed to detect whether a seat belt associated with the vehicle seat is arranged in a closed position or in an open position in which the seat belt and the seat belt buckle are spatially separated from one another. In the closed position, the seat belt is locked into the seat belt buckle so that the seat belt is held in place by the seat belt buckle. The closed position therefore indicates that a person is sitting on the vehicle seat because he or she has buckled the seat belt and the seat belt buckle.

The occupant presence detection device is designed to record presence information and provide it to the evaluation device. The presence information describes a presence of the occupant at a location assigned to the occupant presence detection device, that is, for example, on the vehicle seat in which the pressure sensor and/or on which the seat belt buckle with the seat belt buckle sensor is arranged. The presence information can be recorded in the form of presence data. By means of the occupant presence detection device, the presence of the person at a location in the vehicle assigned to the occupant presence detection device can be detected. The evaluation device can, if necessary, use the presence information for further functions or evaluation steps. It is therefore possible to first determine whether there is a passenger in the vehicle at all and to at least estimate their location. The occupant presence detection device is also a typical component of a vehicle, so that it contributes to realizing a device for determining the mass of the occupant, which can be implemented in the vehicle with little effort.

A further aspect of the invention relates to a vehicle with a vehicle interior in which a device as described above is arranged. The exemplary embodiments described in connection with the device according to the invention, each individually and in combination with one another, apply accordingly, as far as applicable, to the vehicle according to the invention. The vehicle is, for example, a motor vehicle, for example play a passenger car, a truck and/or a passenger bus. The vehicle may alternatively or additionally be another land vehicle, such as a rail vehicle, an aircraft and/or a watercraft.

In addition, one aspect of the invention relates to a method for determining the mass of an occupant of the vehicle. The method has the following steps: determining a vehicle acceleration vector that describes an acceleration experienced by the vehicle using a vehicle acceleration detection device; and determining an occupant acceleration vector that describes an acceleration experienced by the occupant using an occupant acceleration detection device. The occupant acceleration detection device is in particular a different device from the vehicle acceleration detection device. Furthermore, the method provides that an evaluation device is used to determine a vehicle force vector, which describes a force acting on the vehicle, based on the determined vehicle acceleration vector, to project the determined vehicle force vector onto the occupant, and to determine mass information that represents a mass of the occupant describes, from the projected vehicle force vector and the determined occupant acceleration vector. The exemplary embodiments described in connection with the device according to the invention, individually or in combination with one another, apply accordingly, to the extent applicable, to the method according to the invention. Furthermore, combinations of the exemplary embodiments of the device according to the invention described below, individually or in combination, apply in an analogous manner as exemplary embodiments of the method according to the invention.

An exemplary embodiment of the method according to the invention provides that the occupant acceleration detection device is designed as a radar sensor, by means of which a point cloud characteristic of the occupant is detected. The occupant acceleration vector is determined by evaluating the captured point cloud. In other words, when using a radar sensor as an occupant acceleration detection device, the individual occupant appears as a point cloud in the measurement data of the radar device. The point cloud is therefore characteristic of the occupant. The captured point cloud is evaluated to calculate the acceleration acting on the occupant. The evaluation using the radar sensor can be designed for static and/or moving objects. Ultimately, a typical radar sensor can be used to determine the occupant acceleration vector.

Furthermore, one embodiment provides that the characteristic point cloud is continuously recorded. In addition, speed change information, which describes a speed change between at least two point clouds recorded one after the other, is determined and the occupant acceleration vector is determined from the determined speed change information. Based on changes in speed between successive frames, the acceleration experienced by the occupant can be calculated. The change, for example in the speed experienced by the occupant, is preferably taken into account via several point clouds recorded one after the other in order to calculate the acceleration. The speed change information may be provided in the form of data. Therefore, for example, it can alternatively be provided that speed change data is determined.

It can also be provided in one embodiment that a subarea of the captured point cloud, in which the captured point cloud has a highest signal-to-noise ratio compared to the remaining point cloud, is determined. The determined sub-area is assumed to be the center of mass of the occupant's torso. The vehicle force vector is then projected onto a location of the assumed center of mass of the fuselage, that is, onto the sub-area in which the determined center of mass of the fuselage is located. The occupant's torso may alternatively be referred to as the occupant's torso. The torso is the part of the occupant that is not the head, neck, or limb. The procedure described is based on the knowledge that the occupant of the vehicle can, in simple terms, be viewed as a rigid body. By evaluating measurement data from the radar sensor, a center point of the occupant's body mass, i.e. a center of body mass, can be estimated. For this purpose, the center of mass of the fuselage is first determined, as this can be recognized particularly easily in the measurement data from the radar sensor. For this purpose, for example, the measurement data over the entire Doppler spectrum is considered in a distance grid, which, for example, divides at least the distances assigned to the recorded point cloud into several sub-areas. This distance grid contains the measurement data with the highest signal-to-noise ratio at a specific location compared to the remaining measurement data. This location in the distance grid corresponds to the location of the sub-area. A center of the occupant's torso is thus determined by comparing the individual signal-to-noise ratios. These high signal-to-noise ratios can be detected, particularly when the occupant moves. A static object in Vehicle typically does not have a consistently high signal-to-noise ratio, so that by evaluating the signal-to-noise ratios it can also be differentiated, for example, whether it is actually an occupant who may be moving, or a static object, such as a vehicle Object arranged in the vehicle. Ultimately, in addition to the occupant acceleration vector, the occupant's location can be determined using the radar sensor, which in turn is relevant when projecting the determined vehicle force vector onto the occupant, since it is the location onto which the vehicle force vector should be projected. The data from the radar sensor can therefore be evaluated in a particularly versatile manner as part of the process.

Alternatively or additionally, the center of the fuselage can be determined based on the captured point cloud of moving and/or static measuring points in a three-dimensional coordinate system. For example, the areas that are known from the outset as possible sitting positions are evaluated. In these areas, the density of the point cloud and/or the signal-to-noise ratio is evaluated to determine seat occupancy and/or the center of the torso.

In addition, an exemplary embodiment provides that a further subarea of the captured point cloud, in which the captured point cloud has a second-highest signal-to-noise ratio compared to the remaining point cloud, is determined. The further sub-area determined is assumed to be the center of mass of the occupant's head. Taking into account the locations of the assumed center of mass of the trunk and the center of mass of the head, a body of the occupant can be modeled, that is, determined. A center of mass of the modeled body is determined, and the vehicle force vector is projected onto the location of the center of mass determined. The previously described method based on the center of mass of the torso can thus be further refined by taking into account a further local center of gravity of the occupant's body. So not only the sub-area of the point cloud with the highest signal-to-noise ratio is taken into account, but also the sub-area with the second highest signal-to-noise ratio. The occupant is then assumed to be composed of two rigid bodies, the rigid body of the trunk and the rigid body of the head. This increases the accuracy of the location onto which the vehicle force vector is projected, since an overall center of mass of the occupant can be modeled from the estimates of the locations of the head and the torso more precisely than just taking the center of mass of the torso into account. The modeling of the body can be based, for example, on machine learning methods, for example on an artificial neural network, to which information about typical relationships and arrangements of individual centers of mass of an occupant relative to one another, such as the center of mass of the torso and/or the center of mass of the head, has been given as training data.

In a further exemplary embodiment, it is provided that the occupant acceleration detection device is designed as a camera. Camera data is recorded using the camera. The camera data can alternatively be referred to as camera information, which describes an environment of the camera. The camera data describes at least two images of the occupant captured one after the other. These images can be static and/or moving. The images of the occupant may alternatively be referred to as images of the occupant. The occupant acceleration vector is determined by evaluating the captured camera data. For example, a displacement of the occupant over time, that is, between at least two consecutively captured images of the occupant, can be evaluated in order to be able to estimate the occupant acceleration vector. The camera data can be recorded alternatively or in addition to the characteristic point cloud that is captured by the radar device. It is therefore possible for the acceleration vector to be determined, for example, both by means of the radar-based determination and by means of the camera-based determination, so that a particularly reliable determination of the occupant acceleration vector is provided. For example, in this case, an average value of the occupant acceleration vector determined using radar and the occupant acceleration vector determined based on camera can be taken into account as the determined occupant acceleration vector.

Furthermore, an exemplary embodiment provides that when evaluating the camera data, occupant speed change information, which describes a change in the occupant's speed between the at least two images captured one after the other, is determined. The occupant acceleration vector is then determined from the occupant speed change information determined. The occupant speed change information is preferably provided in the form of data. As an alternative to occupant speed change information, occupant speed change data can be determined. So it becomes one through the shifts between the individual images Speed of the occupant closed, whereby a change in this speed over several images, that is over several images, allows the acceleration that the occupant experiences to be calculated. The calculation is based on the physical relationship between speed and acceleration. The calculation of the occupant speed change information from the camera data is based, for example, on image processing methods. Machine learning methods can also be used, for example an appropriately trained artificial neural network. The corresponding evaluation algorithms for both determining the speed change information and for determining the occupant speed change information can be stored in the evaluation device. In a vehicle without a radar sensor in the vehicle interior, which is only equipped with a camera in the vehicle interior, the mass of the occupant can still be determined using the method without retrofitting.

According to an additional exemplary embodiment, it is provided that vehicle mass information is taken into account when determining the vehicle force vector. The vehicle mass information describes a vehicle mass of the vehicle. The vehicle mass information can be provided in the form of data. In other words, vehicle mass data can be taken into account when determining. The vehicle mass information can, for example, be provided from the outset. An entry which describes the vehicle mass of the vehicle can then be stored in a memory unit in the evaluation device. The vehicle mass can be determined, for example, based on an assignment of the vehicle to a specific vehicle model and/or vehicle type. The vehicle mass information provided can be, for example, an empty mass of the vehicle. In this case, additional mass of the vehicle caused by the occupant and/or other objects arranged in the vehicle can be ignored. The vehicle mass information provided can also be dependent on a fill level of a fuel tank of the vehicle if the vehicle has a fuel tank.

Alternatively or additionally, the vehicle mass information can be recorded by the vehicle itself via an internal control device with a connected database and/or by means of a mass capture device. The mass detection device can have at least one mass sensor, which is arranged, for example, in a trunk of the vehicle and is designed to detect and provide a mass of at least one object in the trunk. Together with the stored vehicle mass of the vehicle, which may be an empty vehicle mass of the vehicle, the current vehicle mass information can be estimated more accurately than the stored vehicle mass. The mass detection device can alternatively or additionally be a device external to the vehicle, which is designed, for example, as a scale for a truck or another vehicle onto which the vehicle can drive. Current vehicle mass information can be determined by the device external to the vehicle and, for example, made available to the evaluation device of the vehicle via a wired or wireless communication connection.

If the vehicle mass information is known, the vehicle force vector can be calculated by multiplying the vehicle acceleration vector by the vehicle mass information. This makes it possible for the vehicle force vector to actually be determined from the information determined and/or provided.

In addition, one embodiment provides that a correction algorithm is applied to the vehicle acceleration vector and/or the vehicle force vector. By applying the correction algorithm, an effect of vibrations and/or movement shocks on the vehicle acceleration vector and/or vehicle force vector can at least be reduced. Vibrations and/or movement shocks are observed, for example, while the vehicle is traveling, for example whenever the vehicle is traveling on an uneven surface, such as a cobblestone road. The correction algorithm can have at least one rule that specifies a limit value, so that by applying the rule, the vehicle acceleration vector and/or the vehicle force vector, in particular the measurement data underlying the vehicle acceleration vector and/or the vehicle force vector, are adjusted in such a way that effects due to the currently occurring vibrations, which are typically in the low frequency range, and/or other movement impulses can at least be reduced and preferably completely eliminated. In other words, low-frequency vibrations or movement impulses are ultimately filtered out, so that there is no undesirable influence and in particular falsification of the acceleration and force vector by the vibrations or other movement impulses of the vehicle. The correction algorithm is provided to the evaluation device and is, for example, a computer code, when used by the evaluation device, the corresponding limit value is specified. As a result, the vehicle acceleration vector and/or the vehicle force vector can be provided in a correspondingly adjusted manner.

According to one exemplary embodiment, it is provided that the device has an occupant presence detection device. The occupant presence detection device is in particular a pressure sensor and/or a seat belt buckle sensor. Using the occupant presence detection device, presence information which describes the presence of the occupant at a location assigned to the occupant presence detection device is recorded. Only if the occupant is present according to the recorded presence information is the mass information determined. In other words, the vehicle acceleration vector and/or the occupant acceleration vector and/or the steps for determining the mass information carried out by means of the evaluation device only take place when the occupant is present. Based on the data from the occupant presence detection device, it is first confirmed that an occupant or an object is actually arranged on a vehicle seat of the vehicle. If, for example, according to the recorded presence information, no occupant and/or object is present, carrying out the further method can be dispensed with, so that the method is particularly resource-efficient.

In addition, an exemplary embodiment provides that the detected presence information is taken into account when projecting the vehicle force vector onto the occupant. The presence information in particular has location information that describes the location assigned to the occupant presence detection device. The center of mass of the occupant can therefore be estimated based solely on the position of the vehicle seat on which the occupant sits. The location information describes, for example in the form of a coordinate, a position and/or a position area within the vehicle that is assigned to the vehicle seat. The location information can be provided in the form of data. The location information can therefore alternatively be referred to as location data. The center of mass of the occupant, onto which the vehicle force vector is projected, can thus be based on the presence information and/or based on the above-described evaluation of the sub-areas with the highest and/or second highest signal-to-noise ratio. There are therefore two different options for determining the location to which the vehicle force vector is projected. This makes the process particularly versatile. For example, if no occupant presence detection device is provided in the vehicle, location detection based on the radar data can be used. However, if, for example, the camera-based determination of the occupant acceleration vector takes place, the center of mass of the occupant and thus the location to which the vehicle force vector is projected can still be determined and taken into account without a radar sensor in the vehicle interior, taking into account the data from the occupant presence detection device. Furthermore, this can contribute to saving resources, since the method can be concentrated on the areas of the vehicle where an occupant or at least an object on a vehicle seat is expected.

It should also be noted that the method for determining the mass of the occupant is carried out continuously while the vehicle is traveling and is not only intended, for example, for a momentary event, such as an accident or an abrupt braking of the vehicle caused by some other reason. It is therefore assumed that a continuous and therefore constant detection of the occupant by means of the occupant presence detection device and of the vehicle by means of the vehicle acceleration detection device takes place. When estimating the mass information, a weighted average over several successive acquisitions, for example of the occupant acceleration vectors or rotation vectors, can be taken into account.

It can also be provided that, as an additional degree of freedom, the angular velocity of a yaw, pitch and roll axis is checked using the inertial measuring unit in order to be able to reliably project the vehicle force vector onto the center of mass of the occupant. This is compared to the update rate of the radar sensor to see whether extreme values (spikes) in the magnitude of the acceleration vector are suitable for use in the method. This makes the process even more reliable.

Another aspect relates to a method for determining a mass of an occupant of a vehicle, the method comprising the following steps: providing a vehicle acceleration vector that describes an acceleration experienced by the vehicle; Providing an occupant acceleration vector describing acceleration experienced by the occupant; and by means of an evaluation device: determining a vehicle force vector, which describes a force acting on the vehicle, based on the determined vehicle acceleration vector; Projecting the determined vehicle force vector onto the occupant; and determining mass information describing a mass of the occupant from the projected th vehicle force vector and the determined occupant acceleration vector.

One aspect of the invention relates to the evaluation device for the device. The evaluation device can have a data processing device or a processor device. The processor device can have at least one microprocessor, microcontroller, FPGA (field programmable gate gray) and/or at least one DSP (digital signal processor). Furthermore, the processor device can have program code that is set up to carry out the method according to the invention or an exemplary embodiment of the method according to the invention or a combination of exemplary embodiments of the method according to the invention when executed by the processor device. The program code can be included in a computer program product, i.e. a computer program. The program code can be stored in a data memory of the processor device.

The evaluation device is, for example, a control device of the vehicle. The evaluation device can alternatively or additionally be its own component installed in the vehicle. The evaluation device can alternatively or additionally be an external component that exchanges data with a communication interface of the vehicle. The evaluation device can be included in the vehicle acceleration detection device and/or the occupant acceleration detection device. The evaluation device can have several evaluation units, which are in particular spatially separated from one another, so that individual process steps of the evaluation device can take place in different evaluation units.

Furthermore, one aspect of the invention can relate to a computer-readable storage medium, comprising instructions which, when executed by a computer or a computer network, such as the evaluation device, cause it to carry out the method according to the invention. The storage medium can, for example, be designed at least partially as a non-volatile data storage (e.g. as a flash memory and/or as an SSD - solid state drive) and/or at least partially as a volatile data storage (e.g. as a RAM - random access memory). be. The computer or computer network can provide a processor circuit with at least one microprocessor. The instructions may be provided as binary code or assembler and/or as source code of a programming language (e.g. C).

• 1 eine schematische Darstellung eines Fahrzeugs mit einer Vorrichtung zum Ermitteln einer Masse eines Insassen des Fahrzeugs;
• 2 eine schematische Draufsicht auf im Fahrzeug wirkende Kraftvektoren;
• 3 in schematischer Darstellung einen Signalflussgraphen eines Verfahrens zum Ermitteln einer Masse eines Insassen eines Fahrzeugs;
• 4 eine schematische Draufsicht auf Insassen eines Fahrzeugs mit skizzierten Kopfmassenschwerpunkten; und
• 5 eine schematische Seitenansicht von Insassen eines Fahrzeugs mit skizzierten Rumpfmassenschwerpunkten und Kopfmassenschwerpunkten.

Show:

• 1 a schematic representation of a vehicle with a device for determining a mass of an occupant of the vehicle;
• 2 a schematic top view of force vectors acting in the vehicle;
• 3 a schematic representation of a signal flow graph of a method for determining a mass of an occupant of a vehicle;
• 4 a schematic top view of occupants of a vehicle with outlined head mass centers; and
• 5 a schematic side view of occupants of a vehicle with outlined torso centers of mass and head centers of mass.

1 shows a vehicle 1, which is designed here as a motor vehicle, in particular as a passenger car. There are two occupants 2 in the vehicle 1, one of whom is arranged as a driver in a driver's seat 3 and the other as a passenger in a passenger seat 4. The vehicle 1 also has several rear seats 5. Alternative numbers and arrangements of the occupants 2 in the vehicle 1 are possible. The arrangement of the two occupants 2 in a front area of the vehicle 1 described here is to be understood purely as an example.

The vehicle 1 has a device 6 for determining a mass of an occupant 2 of the vehicle 1. The device 6 has a vehicle acceleration detection device 7. An acceleration sensor 8 and an inertial measuring unit 9, which can alternatively be referred to as an inertial sensor, are sketched here as the vehicle acceleration detection device 7. The two options for the vehicle acceleration detection device 7 are here, by way of example, arranged approximately centrally in both a longitudinal direction (x-direction) and in a transverse direction (y-direction) of the vehicle 1. At least the inertial measuring unit 9 is preferably arranged at the location of a vehicle center of mass of the vehicle 1.

The device 6 also has an occupant acceleration detection device 10. The occupant acceleration detection device 10 is designed, for example, as a radar sensor 11 and/or as a camera 12. Both the radar sensor 11 and the camera 12 are designed to detect a vehicle interior of the vehicle 1. They are therefore positioned, for example, approximately centrally in the longitudinal and transverse directions in the area of a ceiling of the vehicle 1, that is, for example, integrated into a vehicle headliner of the vehicle 1. In particular, a position of the radar sensor 11 and the camera 12 is selected such that by means of the radar sensor 11 respectively the camera 12 can detect all possible occupants 2 of the vehicle 1. Therefore, at least partially, both the driver's seat 3 and the passenger seat 4 as well as the rear seats 5 are in a detection range of the radar sensor 11 or the camera 12.

The device 6 also has an evaluation device 13. The evaluation device 13 can be a component of the vehicle 1, that is, for example, a control device or another type of computing device of the vehicle 1. The evaluation device 13 can have at least one microprocessor and/or microcontroller and thus be designed, for example, as a computer.

The vehicle 1 can have an occupant presence detection device 14, which is sketched here as an example for the front passenger seat 4. The occupant presence detection device 14 may have a pressure sensor 15, which is integrated into the front passenger seat 4, and/or a seat belt buckle sensor 16 for a seat belt 39 of the front passenger seat 4. The seat belt buckle sensor 16 is designed to detect a closed position of the seat belt 39. The pressure sensor 15 can detect a pressure that is exerted on the passenger seat 4 and thus determine whether, for example, an occupant 2 or another object is positioned on the passenger seat 4 or not. Analogous to this, the occupant presence detection device 14 can be provided for the driver's seat 3 and/or a respective rear seat 5 in the vehicle 1 (not outlined here).

In 2 a top view of the two occupants 2 in the vehicle 1 is sketched. The inertial measuring unit 9 is arranged at the location of the vehicle's center of mass of the vehicle 1. In addition, for example, the acceleration sensor 8, which is comprised, for example, by an acceleration measuring device, is shown. The acceleration sensor 8 can be arranged at any location in the vehicle 1. For example, it can be arranged spatially close to the occupant acceleration detection device 10.

In 2 Several coordinate systems are shown, namely an acceleration sensor coordinate system 17, which represents a local coordinate system of the acceleration sensor 8, a measuring unit coordinate system 18, which represents a local coordinate system of the inertial measuring unit 9, and occupant coordinate systems 19 for each of the two occupants 2 are outlined. The occupant coordinate systems 19 each represent the local coordinate system of the occupant 2. The respective occupant coordinate system 19 has an origin in a center of mass 20 of the respective occupant 2. Each of the sketched coordinate systems has an x-axis, a y-axis and a z-axis, that is, different axes for Cartesian coordinates.

In 2 Several force vectors are also sketched. Two of the force vectors are a vehicle force vector 21, which was determined either using the measurement data of the acceleration sensor 8 or using the measurement data of the inertial measuring unit 9. The two vehicle force vectors 21 shown here therefore differ, for example, in their magnitude and in their direction, which is due to the fact that they are specified in their respective local coordinate system, that is, in the acceleration sensor coordinate system 17 or in the measuring unit coordinate system 18. Furthermore, in 2 a projected vehicle force vector 22 is outlined, which represents a projection of the vehicle force vector 21 of the acceleration sensor 8 and/or the inertial measuring unit 9 onto the center of mass 20 of the respective occupant 2. The vehicle force vector 21 in the acceleration sensor coordinate system 17 may be represented as vector F _Acc , the vehicle force vector 21 in the measurement unit coordinate system 18 as vector F _IMU , the projected vehicle force vector 22 for the occupant 2 on the driver's seat 3 as vector F _X , and the projected vehicle force vector 22 for the occupant 2 on the Passenger seat 4 can be referred to as vector F _Y.

3 shows method steps of a method for determining the mass of the occupant 2 of the vehicle 1. The method can be used, for example, for the two occupants 2 of the vehicle 1 1 and 2 be applied. In a method step S1, it can be provided that presence information 23 is determined by means of the occupant presence detection device 14, which describes a presence of the occupant 2 at a location assigned to the occupant acceleration detection device 10, such as a location of the front passenger seat 4 or the driver's seat 3. It can then be checked in a method step S2 whether an occupant 2 is actually present in the vehicle 1 according to the determined presence information 23. If this is the case, method steps S3 and S4 can take place. If, for example, no occupant 2 is arranged in the vehicle 1, that is to say the checking is not successful, method step S1 can be carried out again, for example until the presence of the occupant 2 is detected.

In method step S3, a vehicle acceleration vector 24 is determined by means of the vehicle acceleration detection device 7. The vehicle acceleration vector 24 describes one experienced by the vehicle 1 Acceleration. A correction algorithm 25 can be applied to the vehicle acceleration vector 24 in order to at least reduce an effect of vibration and/or movement shocks of the vehicle 1 on the vehicle acceleration vector 24.

In method step S4, an occupant acceleration vector 26, which describes an acceleration experienced by the occupant 2, is determined by means of the occupant acceleration detection device 10. The occupant acceleration detection device 10 is different from the vehicle acceleration detection device 7.

Preceding method step S4, for example, a method step S5 can take place if the occupant acceleration detection device 10 is designed as the radar sensor 11. Using the radar sensor 11, a point cloud 27 that is characteristic of the occupant 2 is then detected, that is, a collection in measurement data from the radar sensor 11 is determined. The captured point cloud 27 is then evaluated in order to determine the occupant acceleration vector 26. For this purpose, in a method step S6, speed change information 28 is determined, which describes a speed change between at least two point clouds 27 recorded one after the other. The occupant acceleration vector 26 is determined from the determined speed change information 28. The acceleration of the occupant 2 is therefore concluded based on the observed change in speed over time.

Alternatively or in addition to method steps S5 and S6, method steps S7 and S8 can be carried out. In method step S7, the camera 12 is used to capture camera data 29, which describe at least two images of the occupant 2 captured one after the other. The occupant acceleration vector 26 can now be determined by evaluating the captured camera data 29. For this purpose, in method step S8, occupant speed change information 30 is determined, which describes a change in speed of the occupant 2 between the at least two images captured one after the other. The occupant acceleration vector 26 is determined from the determined occupant speed change information 30, with the acceleration again being inferred based on the change in speed over time.

In a method step S9, the vehicle force vector 21, which describes the force acting on the vehicle 1, is determined. This is done based on the determined vehicle acceleration vector 24. In addition, to determine the vehicle force vector 21, vehicle mass information 31, which describes a vehicle mass of the vehicle 1, is taken into account. The vehicle mass information 31 can be provided and/or detected using a mass detection device. In method step S9, the correction algorithm 25 can also be taken into account.

The method step S9 is carried out using the evaluation device 13. It can also be provided that the evaluation steps S6 and S8 take place using the evaluation device 13. It can further be provided that the determination of the vehicle acceleration vector 24 and the occupant acceleration vector 26 in the method steps S3 and S4 also takes place at least with the participation of the evaluation device 13, whereby data from the vehicle acceleration detection device 7 and / or the occupant acceleration detection device 10 are provided for this purpose, which are then provided by the evaluation device 13 can be evaluated accordingly.

In a method step S10, the determined vehicle force vector 21 is projected onto the occupant 2 by means of the evaluation device 13, whereby the projected vehicle force vector 22, which can alternatively be referred to as an occupant force vector, is calculated. The location onto which the vehicle force vector 21 is projected can be predetermined, for example, based on the presence information 23, which can have location information 32 for this purpose, which describes the location to which the occupant presence detection device 14 is assigned. Alternatively or additionally, the location onto which the vehicle force vector 21 is projected may be a location of a fuselage center of mass 33. The torso center of mass 33 is a center of gravity of a torso of the occupant 2 and can be determined based on the data from the radar sensor 11. Alternatively or additionally, a body center of mass 35 can be taken into account, which is determined from the torso center of mass 33 and a head center of mass 34, which describes the center of mass 20 of a head of the occupant 2. The body center of mass 35 is, for example, a more precise center of mass 20 of the occupant 2 than the torso center of mass 33 alone.

In a method step S11, mass information 36, which describes the mass of the occupant 2, is determined by means of the evaluation device 13. The mass information 36 is determined from the projected vehicle force vector 22 and the determined occupant acceleration vector 26. The mass information 36 determined here is typical Actually, only an estimated mass of the occupant 2. This means that, depending on the range of values, for example, between a small child who weighs less than 10 kilograms, a child who weighs between more than 10 kilograms and less than 50 kilograms, and an adult who weighing more than 50 kilograms can be distinguished. The estimated mass can be evaluated, for example, for an airbag control of an airbag of the vehicle 1 and/or for a warning device that warns about passengers 2 left behind in the vehicle 1, in particular if they are the child or toddler. The corresponding warning can be displayed, for example, in an application on a mobile device of a user of the vehicle 1.

4 and 5 show the individual centers of gravity 20 of the two occupants 2 on the driver's seat 3 and the passenger seat 4 from two different perspectives 4 the center of mass of the head 34 can be seen in each case. 5 In contrast, shows both the head center of mass 34 and the respective torso center of mass 33 of the respective occupant 2. In both 4 and 5 a direction of travel 37 of the vehicle 1 and various individual sub-areas 38 are shown in the detection range of the radar sensor 11, which are sketched here as a grid.

The center of mass of the fuselage 33 can be determined as follows: The sub-area 38 of the captured point cloud 27 is determined in that the captured point cloud 27 has a highest signal-to-noise ratio compared to the remaining point cloud 27. The determined sub-area 38 is then assumed to be the center of mass 33 of the torso of the occupant 2. The vehicle force vector 21 can be projected onto the location of the assumed center of mass of the fuselage 33. It is additionally or alternatively possible for a further sub-area 38 of the captured point cloud 27 to be determined in that the captured point cloud 27 has a second-highest signal-to-noise ratio compared to the remaining point cloud 27. The determined further sub-area 38 is assumed to be the center of mass 34 of the head of the occupant 2. If the location of the assumed center of mass of the torso 33 and the location of the assumed center of mass of the head 34 are now taken into account, the body of the occupant 2 can be modeled. In this model, a center of mass 35 of the modeled body can be determined, which is then viewed as the location to which the vehicle force vector 21 is projected.

Overall, the examples show a mass estimate for vehicle interior passengers, that is, the occupants 2, based on the acceleration sensor 8 and/or the inertial measuring unit 9. For this purpose, the device 6 has the acceleration sensor 8 and/or the inertial measuring unit 9, that is, an inertial sensor Vehicle 1, which in each case determines an acceleration vector of the vehicle 1, that is to say the vehicle acceleration vector 24. The device 6 furthermore has at least the radar-based detection device for detecting occupants 2 in the vehicle interior, that is to say at least the radar sensor 11 as the occupant acceleration detection device 10. This delivers For each detected occupant 2, a point cloud from which the acceleration of the occupant 2 in question can be estimated. By projecting the determined acceleration vector of the vehicle 1 onto the occupant 2, which is in the vehicle force vector 21, it is possible, for example, to draw conclusions about the mass of the occupant 2 in question. The mass information 36 of the individual occupant 2 can therefore be estimated without additional hardware and/or without additional additions to existing functions. This ultimately makes it possible to set comfort settings, such as the automatic adjustment of a seat to support the occupant 2, especially when cornering, in order to avoid massive deflection of the body. In addition, other applications are conceivable, such as individual deployment of an airbag based on the expected mass and/or possibly size.

Claims (15)

Device (6) for determining a mass of an occupant (2) of a vehicle (1), the device (6) having: - a vehicle acceleration detection device (7) which is designed to determine a vehicle acceleration vector (24) which describes an acceleration experienced by the vehicle (1); - an occupant acceleration detection device (10), which is designed to determine an occupant acceleration vector (26) which describes an acceleration experienced by the occupant (2); and - an evaluation device (13) which is designed, based on the determined vehicle acceleration vector (24), to determine a vehicle force vector (21), which describes a force acting on the vehicle (1), the vehicle force vector (21) on the occupant ( 2) to project and to determine mass information (36), which describes a mass of the occupant (2), from the projected vehicle force vector (22) and the determined occupant acceleration vector (26). Device (6) after Claim 1 , characterized in that the occupant acceleration Supply detection device (10) is designed as a radar sensor (11) and / or camera (12). Device (6) according to one of the preceding claims, characterized in that the vehicle acceleration detection device (7) is designed as an acceleration sensor (8) and/or inertial measuring unit (9). Device (6) according to one of the preceding claims, characterized in that the device (6) has an occupant presence detection device (14), in particular a pressure sensor (15) and/or a seat belt buckle sensor (16), which is designed to provide presence information ( 23), which describes the presence of the occupant (2) at a location assigned to the occupant presence detection device (14), and to provide it to the evaluation device (13). Method for determining a mass of an occupant (2) of a vehicle (1), the method having the following steps: - Determining (S3) a vehicle acceleration vector (24), which describes an acceleration experienced by the vehicle (1), by means of a vehicle acceleration detection device (7); - Determining (S4) an occupant acceleration vector (26), which describes an acceleration experienced by the occupant (2), by means of an occupant acceleration detection device (10); - by means of an evaluation device (13): - Determining (S9) a vehicle force vector (21), which describes a force acting on the vehicle (1), based on the determined vehicle acceleration vector (24); - Projecting (S10) the determined vehicle force vector (21) onto the occupant (2); and - Determining (S11) mass information (36), which describes a mass of the occupant (2), from the projected vehicle force vector (22) and the determined occupant acceleration vector (26). Procedure according to Claim 5 , characterized in that the occupant acceleration detection device (10) is designed as a radar sensor (11), by means of which a point cloud (27) characteristic of the occupant (2) is detected (S5), the occupant acceleration vector (S5) being determined by evaluating the detected point cloud (27). 26) is determined. Procedure according to Claim 6 , characterized in that the characteristic point cloud (27) continuously detects, determines (S6) a speed change information (28) which describes a speed change between at least two point clouds (27) recorded one after the other, and from the determined speed change information (28) the occupant acceleration vector ( 26) is determined. Procedure according to one of the Claims 6 or 7 , characterized in that a sub-area (38) of the captured point cloud (27), in which the captured point cloud (27) has a highest signal-to-noise ratio compared to the remaining point cloud (27), is determined, the determined sub-area (38) is assumed to be the center of mass (33) of a torso of the occupant (2) and the vehicle force vector (21) is projected onto a location of the assumed center of mass (33). Procedure according to Claim 8 , characterized in that a further sub-area (38) of the captured point cloud (27), in which the captured point cloud (27) has a second highest signal-to-noise ratio compared to the remaining point cloud (27), is determined, the determined further sub-area ( 38) assumed as the head center of mass (34) of a head of the occupant (2), taking into account the locations of the assumed center of mass of the torso (33) and the assumed center of mass of the head (34), a body of the occupant (2) is modeled, a center of mass (35) of the modeled body determined and the vehicle force vector (21) is projected onto the location of the determined center of mass (35). Procedure according to one of the Claims 5 until 9 , characterized in that the occupant acceleration detection device (10) is designed as a camera (12), by means of which camera data (29) are captured (S7), which describe at least two images of the occupant (2) captured one after the other, and by evaluating the captured ones Camera data (29) determines the occupant acceleration vector (26). Procedure according to Claim 10 , characterized in that when evaluating the camera data (29), occupant speed change information (30), which describes a change in speed of the occupant (2) between the at least two images captured one after the other, is determined and the occupant acceleration vector (26) is derived from the determined occupant speed change information (30). is determined (S8). Procedure according to one of the Claims 5 until 11 , characterized in that when determining the vehicle force vector (21), vehicle mass information (31), which describes a vehicle mass of the vehicle (1), is taken into account, the vehicle mass information (31) being available is provided and/or is detected by means of a mass detection device. Procedure according to one of the Claims 5 until 12 , characterized in that a correction algorithm (25) is applied to the vehicle acceleration vector (24) and / or the vehicle force vector (21), whereby an effect of vibrations and / or movement shocks on the vehicle acceleration vector (24) and / or vehicle force vector (21) at least is reduced. Procedure according to one of the Claims 5 until 13 , characterized in that the device (6) has an occupant presence detection device (14), in particular a pressure sensor (15) and / or a seat belt buckle sensor (16), by means of which presence information (23) indicates the presence of the occupant (2). describes a location assigned to the occupant presence detection device (14), is detected (S1), the mass information (36) being determined only if the occupant (2) is present (S2) according to the detected presence information (23). Procedure according to Claim 14 , characterized in that when projecting the vehicle force vector (21) onto the occupant (2), the detected presence information (23) is taken into account, the presence information (23) in particular having location information (32) which corresponds to the location assigned to the occupant presence detection device (14). describes.

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